After unsuccessfully trying to run a HP fuel pump from a sump in the tank, I installed a LP pump and swirl pot. Due to the low miles I figured I would
save money and buy a cheap LP pump, it's mounted directly on the ally rear bulkhead (car is Westfield)
The whole system works but the LP pump is very noisey, so I'm after any advice;
1) If I purchase a more expensive LP pump will it be quiter
2) I'm going to move the mounting off the aluminium bulkhead and add some rubber, is there anything else I can do to make it quieter?
Any other suggestions are gratefully received.
Thanks
Carl
Mount it on rubber bobbin mounts would help
As Ian says rubber mount it, but also try and mount it on the chassis or close to a chassis mount, so as to reduce the soundboard effect of the panels.
This is not something I know a lot about, but maybe I have a suggestion that others with more knowledge can comment on.
My setup is low pressure pump (Facet, solid-state) and carb, which spills back excess flow from the carb to the tank via a small orifice, but I have
noticed that the pump is very noisy when turned on, then really quietens after a few seconds. It seems that it needs a few psi of back-pressure before
it will quieten down.
In your case, the breather from the pot to the tank won't provide any noticeable back-pressure, so you could try a different type of pump or put
a restriction in the breather line. The latter should quieten once the pot is fully liquid filled, but the pump flow should still push vapours out
with no problem (just as with the carb supply).
You'd still get noise whenever there was vapour there, but probably not when settled at low revs - and who cares when high revs overpower the
pump noise anyway!
You'd need to experiment a little with the orifice size, so as to get the highest flow, with just sufficient back pressure to stop the noise.
You'd also need to investigate if your injectors are okay with a slight pressure on their return line.
quote:
Originally posted by SteveWalker
This is not something I know a lot about, but maybe I have a suggestion that others with more knowledge can comment on.
My setup is low pressure pump (Facet, solid-state) and carb, which spills back excess flow from the carb to the tank via a small orifice, but I have noticed that the pump is very noisy when turned on, then really quietens after a few seconds. It seems that it needs a few psi of back-pressure before it will quieten down.
In your case, the breather from the pot to the tank won't provide any noticeable back-pressure, so you could try a different type of pump or put a restriction in the breather line. The latter should quieten once the pot is fully liquid filled, but the pump flow should still push vapours out with no problem (just as with the carb supply).
You'd still get noise whenever there was vapour there, but probably not when settled at low revs - and who cares when high revs overpower the pump noise anyway!
You'd need to experiment a little with the orifice size, so as to get the highest flow, with just sufficient back pressure to stop the noise. You'd also need to investigate if your injectors are okay with a slight pressure on their return line.
There are a certain type of LP pumps you can get that are dramatically quieter, but be prepared to pay for it, and i'm not sure what they are.
I do remember reading something on here ages ago actually that people were putting restrictors or similar in the return line from the swirl pot to the
tank which improves the situation a fair amount.
if it isn't a facet cube but a copy, it could have a very short life anyway (a mate bought one, lasted less than an hour! replacement has now
done a few hundred miles, but I would be nervous)
You could try a facet posiflow, rather quieter by design and not expensive
If the HP one did not work well in the same place it would suggest you are pulling in air, this makes them very noisy !
Thanks for all your replies, plenty for me to try. I'll report back in a few days.